Effective borehole design in difficult crystalline rock terrain; a case study of the Abakaliki pyroclastic rocks

Abstract

The Ebonyi State Police Headquarters, Abakaliki is within the area underlain by the pyroclastic rocks that are generally known to have low prospect for groundwater. Yet, a borehole with sustainable yield was required to supply part of the increased population of the barracks through a newly constructed 40,000 litres capacity overhead tank


Modified borehole design and yield enhancement procedure along with pre- drilling electrical resistivity survey were used to achieve sustained yield of 1500 litres per hour from a motorized borehole.


KEY WORDS: Pyroclastic rocks; borehole design; sustainable yield.


Global Journal of Geological Sciences Vol.2(2) 2004: 183-190